An increasing number of applications today make use of digital video signals for various purposes including, for example, business meetings between people in remote locations via video conferencing, high definition video entertainment, video advertisements, and sharing of user-generated videos. As technology is evolving, users have higher expectations for video quality and resolution even when video signals are transmitted over communications channels having limited bandwidth.
To permit transmission of digital video streams while limiting bandwidth consumption, a number of video compression schemes have been devised, including formats such as VPx, promulgated by Google Inc. of Mountain View, Calif., and H.264, a standard promulgated by ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG), including present and future versions thereof. H.264 is also known as MPEG-4 Part 10 or MPEG-4 AVC (formally, ISO/IEC 14496-10).
These compression schemes can use quantization techniques on frames of a digital video stream to reduce the bitrate (i.e. data size) of the encoded digital video stream. These quantization techniques discard part of a frame's data using standard computations, thereby reducing the frame's bitrate. Although these quantization techniques reduce the bitrate, they may not suitably maintain the quality of the video signal.